Slice forecast and its accuracy criterion

Subject. This article provides a mathematical formulation of a slice-based forecast technique allowing a comprehensive assessment of future changes in the dynamics and structure of economic systems. The technique is based on an analysis and integration of a set of time series of heterogeneous indicators combined in a system logical algorithm of information synthesis called a slice. A slice forecast accuracy criterion is proposed as well. Objectives. Slice forecasts are designed to improve the quality and efficiency of economic forecasts. Methods. The slice forecast technique is based on a slice technology as a set of methods to collect, process, analyze, and synthesize information and knowledge. Results. The article presents a calculation based on eight series of macroeconomic indicators that characterize the development of the economy of the Russian Federation for the period from 2000 to 2021. It shows new possibilities of analysis and description of economic systems, cycles and crisis phenomena. Conclusions. The results obtained show that the slice technique helps solve a number of urgent problems to improve the quality of foreseeing future changes.

Trading accuracy for speed over the course of a decision

Humans and other animals often need to balance the desire to gather sensory information (to make the best choice) with the urgency to act, facing a speed-accuracy tradeoff (SAT). Given the ubiquity of SAT across species, extensive research has been devoted to understanding the computational mechanisms allowing its regulation at different timescales, including from one context to another, and from one decision to another. However, animals must frequently change their SAT on even shorter timescales - i.e., over the course of an ongoing decision - and little is known about the mechanisms that allow such rapid adaptations. The present study aimed at addressing this issue. Human subjects performed a decision task with changing evidence. In this task, subjects received rewards for correct answers but incurred penalties for mistakes. An increase or a decrease in penalty occurring halfway through the trial promoted rapid SAT shifts, favoring speeded decisions either in the early or in the late stage of the trial. Importantly, these shifts were associated with stage-specific adjustments in the accuracy criterion exploited for committing to a choice. Those subjects who decreased the most their accuracy criterion at a given decision stage exhibited the highest gain in speed, but also the highest cost in terms of performance accuracy at that time. Altogether, the current findings offer a unique extension of previous work, by suggesting that dynamic changes in accuracy criterion allow the regulation of the SAT within the timescale of a single decision.

Improved Velocity Estimation Method for Doppler Sonar Based on Accuracy Evaluation and Selection

The matched filtering method and the waveform-tracking method cannot maintain optimal velocity estimation performance all of the time. In order to solve this problem, this paper proposes an improved velocity estimation method for Doppler sonar, based on accuracy evaluation and selection. The echo of Doppler sonar is divided into several segments with the same width as the transmitted pulse, and each segment is regarded as the echo of the corresponding water layer. According to our study’s results, the velocity estimation accuracy of each segment is positively correlated with the ratio of its autocorrelation modulus to its power. Based on this conclusion, a velocity accuracy criterion with high accuracy and low complexity is designed in order to select the optimal velocity estimation for water layers or bottoms. The proposed accuracy selection method flexibly selects the echo interval to be processed according to the accuracy criterion, so as to maintain the optimal estimation of the current’s or bottom’s velocity. Water tank and field experiments using a prototype Doppler sonar device demonstrates that, compared with the matched filtering method and the waveform-tracking method, the average velocity estimation accuracy and bias of the proposed method are superior.

Сomparative study of the accuracy of Earth observation by satellite constellations in high elliptical orbits

The paper provides results of estimated accuracy comparisons for applied satellite constellations (ASC) in Molniya-type high elliptical orbits based on a previously presented criterion for analysis of accuracy parameters of ASC that observe targets on the Earth surface and/or in the layer above the surface, which is not dependent on specific features of the onboard equipment, but rather on the structure and dynamics of the ASC. The paper provides an algorithm for numerical simulations of ASC. The paper discusses accuracy parameters for ASC in high elliptical orbits in various orbital configurations, as well as a combined option involving spacecraft in geostationary orbit. It defines key trajectory design parameters driving the ASC accuracy. The results can be used for selecting the initial ASC configuration in high elliptical orbits during preliminary design phase. Key words: observation satellite systems, high elliptical orbits, accuracy criterion, satellite constellation analysis.

COMPARATIVE STUDY OF THE ACCURACY OF EARTH OBSERVATION BY SATELLITE CONSTELLATIONS IN HIGH ELLIPTICAL ORBITS

The paper provides results of estimated accuracy comparisons for applied satellite constellations (ASC) in Molniya-type high elliptical orbits based on a previously presented criterion for analysis of accuracy parameters of ASC that observe targets on the Earth surface and/or in the layer above the surface, which is not dependent on specific features of the onboard equipment, but rather on the structure and dynamics of the ASC. The paper provides an algorithm for numerical simulations of ASC. The paper discusses accuracy parameters for ASC in high elliptical orbits in various orbital configurations, as well as a combined option involving spacecraft in geostationary orbit. It defines key trajectory design parameters driving the ASC accuracy. The results can be used for selecting the initial ASC configuration in high elliptical orbits during preliminary design phase. Key words: observation satellite systems, high elliptical orbits, accuracy criterion, satellite constellation analysis.

Structural-parametric synthesis of the tracking filter based on decomposition by the target functional with adaptation to trajectory disturbances

Traditional Kalman-type tracking filters are based on a kinematic motion model, which leads to the occurrence of dynamic errors, which significantly increase during target maneuvering. One of the solutions to this problem is to develop a model of motion dynamics with the ability to adapt its structure to external influences. It is shown that the use of a dynamic model of motion in the filter, which takes into account the inertia of the target and the forces acting on it, makes it possible to significantly increase the efficiency of the state assessment. Purpose is to development of an algorithm for assessing the position of a maneuvering object, effective in terms of accuracy criterion. The use of an adaptive motion model as part of the filter provides an increase in the estimation accuracy in comparison with the classical Kalman filter, which is confirmed by the performed numerical modeling.

Phoneme and Stress Programming Interact During Nonword Repetition Learning

Purpose Lexical stress and phoneme processes converge during phonological encoding, but the nature of the convergence has been debated. Stress patterns and phonemes may be integrated automatically and rigidly, resulting in a unified representation. Alternatively, stress and phoneme may be processed interactively based on sublexical contexts. The purpose of this study was to evaluate the extent to which the lexical stress and phoneme processing interact in a novel nonword learning paradigm. Method Twenty-seven adults with typical speech skills were trained to produce nonwords with specific phonemes, syllables, and stress patterns (Set 1) to an accuracy criterion. Then, participants repeated nonwords that varied from Set 1 in syllable position (Set 2), phoneme sequence (Set 3), included new phonemes (Set 4), or had new phonemes and stress patterns (Set 5). Nonword productions were perceptually analyzed, and phoneme and stress errors were counted. Results Participants' produced Set 1 nonwords with few phonemic or stress errors after training; a similar number of both types of errors were produced when comparing Sets 2 and 3. Greater phoneme and stress errors were produced on nonwords from Sets 4 and 5 compared to Sets 1–3. The highest number of phonemic errors occurred in Set 4 nonwords. There was no difference in the number of stress errors produced on nonwords in Sets 4 and 5. Conclusion The results of this study suggested that lexical stress and phoneme processing co-occurred and interacted during nonword productions. Trained stress patterns were learned during training; however, no evidence for a unified representation was observed. Negative interference was observed in nonwords with new phonemes and trained stress patterns, suggesting online phoneme processing may have dominated and interfered with the retrieval of stored metrical frames.

Dynamic changes in urgency over the course of a decision

While making decisions, humans and other animals always need to balance the desire to gather sensory information (to make the best choice) with the urge to act, facing a speed-accuracy tradeoff (SAT). Given the ubiquity of the SAT across species, extensive research has been devoted to understanding the computational mechanisms allowing its regulation at different timescales, including from one context to another, and from one decision to another. However, in dynamic environments, animals often need to change their SAT on even shorter timescales – i.e., over the course of an ongoing decision – and very little is known about the mechanisms that allow such rapid adaptations. The present study aimed at addressing this issue. Human subjects performed a modified version of the tokens task, where an increase or a decrease in penalty occurring halfway through the trial promoted rapid SAT shifts, favoring speeded decisions either in the early or in the late stage of the trial. Importantly, these shifts were associated with stage-specific adjustments in the accuracy criterion exploited for committing to a choice and relatedly, with dynamic, non-linear changes in urgency. Those subjects who decreased the most their accuracy criterion at a given decision stage presented the highest gain in speed, but also the highest cost in terms of accuracy at that time. Altogether, the current findings offer a unique extension of former work, by revealing that dynamic changes in urgency allow the regulation of the SAT within the timescale of a single decision.

Accuracy criterion and analysis of continuous earth observation constellations

A criterion for analyzing the accuracy characteristics of applied satellite constellations (ASC) possible structures for observing targets in the Earth surface and/or near-surface layer is proposed. The criterion is not related to features of onboard hardware and depends on structure, parameters and dynamics of ASC. The criterion is based on consideration of determination accuracy of the objects geographical coordinates. An algorithm for numerical simulation of ASC is presented. Comparative accuracy estimates for various types of ASC are presented. Accuracy characteristics of Walker constellations and Near-Polar Satellite Constellations with various pattern types are considered. The main design-ballistic parameters that determine the accuracy of ASC and affect the cost of their creation are determined, and the nature of these parameters influence also shown. Results can be used for initial decision of ASC pattern during preliminary design stage. Key words: observing satellite constellations, accuracy criterion, analysis of observation constellations, Walker constellations, Near-Polar Satellite Constellations.